Background: Avulsion of the proximal hamstring origin is well documented, and surgical treatment is advocated for complete avulsions., Purpose: To compare the return to preinjury level of sport and the complexity of surgery in athletes undergoing surgical intervention for complete proximal hamstring avulsions within 6 weeks, 6 months, and after 6 months of injury., Study Design: Case series; Level of evidence, 4., Methods: This was the largest case series from a tertiary referral center reported in the literature. A total of 112 athletes were included, with complete proximal avulsion injuries confirmed on MRI scans; 63 patients (56.3%) were high-level athletes. Patients were divided into subgroups depending on the timing of surgical intervention: "early" was defined within 6 weeks, "delayed" within 6 weeks to 6 months, and "late" after 6 months. All patients were surgically explored and repaired with the aim of comparing the timing between each group and the return to preinjury sport. All patients underwent an individualized rehabilitation protocol. There was no loss to follow-up. The primary outcome measure was the return to preinjury level sports activity., Results: A total of 108 patients (96.4%) returned to sport. In the early intervention group, the average time of return to play was 16 weeks, 9 weeks faster than the delayed group and 13 weeks faster than the late group. There were 2 partial reruptures in those with delayed intervention—both athletes retired from competitive sport but were recreationally active. Two other athletes recovered well but retired from playing at all levels. Twelve athletes (2 in the early intervention group, 5 in the delayed, 5 in the late) were delayed by local nerve symptoms. Only 2 cases required further exploration., Conclusion: Early surgical intervention was associated with good clinical outcomes and a quicker return to sport; however, delaying the diagnosis can lead to prolonged morbidity and an increased likelihood of complications., (© 2014 The Author(s).)